1 files changed, 129 insertions, 0 deletions
diff --git a/searx/engines/wolframalpha_api.py b/searx/engines/wolframalpha_api.py
new file mode 100644
index 0000000..595c6b7
--- /dev/null
+++ b/searx/engines/wolframalpha_api.py
@@ -0,0 +1,129 @@
+# Wolfram Alpha (Science)
+#
+# @website     https://www.wolframalpha.com
+# @provide-api yes (https://api.wolframalpha.com/v2/)
+#
+# @using-api   yes
+# @results     XML
+# @stable      yes
+# @parse       url, infobox
+
+from lxml import etree
+from searx.url_utils import urlencode
+
+# search-url
+search_url = 'https://api.wolframalpha.com/v2/query?appid={api_key}&{query}'
+site_url = 'https://www.wolframalpha.com/input/?{query}'
+api_key = ''  # defined in settings.yml
+
+# xpath variables
+failure_xpath = '/queryresult[attribute::success="false"]'
+input_xpath = '//pod[starts-with(attribute::id, "Input")]/subpod/plaintext'
+pods_xpath = '//pod'
+subpods_xpath = './subpod'
+pod_primary_xpath = './@primary'
+pod_id_xpath = './@id'
+pod_title_xpath = './@title'
+plaintext_xpath = './plaintext'
+image_xpath = './img'
+img_src_xpath = './@src'
+img_alt_xpath = './@alt'
+
+# pods to display as image in infobox
+# this pods do return a plaintext, but they look better and are more useful as images
+image_pods = {'VisualRepresentation',
+              'Illustration'}
+
+
+# do search-request
+def request(query, params):
+    params['url'] = search_url.format(query=urlencode({'input': query}), api_key=api_key)
+    params['headers']['Referer'] = site_url.format(query=urlencode({'i': query}))
+
+    return params
+
+
+# replace private user area characters to make text legible
+def replace_pua_chars(text):
+    pua_chars = {u'\uf522': u'\u2192',  # rigth arrow
+                 u'\uf7b1': u'\u2115',  # set of natural numbers
+                 u'\uf7b4': u'\u211a',  # set of rational numbers
+                 u'\uf7b5': u'\u211d',  # set of real numbers
+                 u'\uf7bd': u'\u2124',  # set of integer numbers
+                 u'\uf74c': 'd',        # differential
+                 u'\uf74d': u'\u212f',  # euler's number
+                 u'\uf74e': 'i',        # imaginary number
+                 u'\uf7d9': '='}        # equals sign
+
+    for k, v in pua_chars.items():
+        text = text.replace(k, v)
+
+    return text
+
+
+# get response from search-request
+def response(resp):
+    results = []
+
+    search_results = etree.XML(resp.text)
+
+    # return empty array if there are no results
+    if search_results.xpath(failure_xpath):
+        return []
+
+    try:
+        infobox_title = search_results.xpath(input_xpath)[0].text
+    except:
+        infobox_title = ""
+
+    pods = search_results.xpath(pods_xpath)
+    result_chunks = []
+    result_content = ""
+    for pod in pods:
+        pod_id = pod.xpath(pod_id_xpath)[0]
+        pod_title = pod.xpath(pod_title_xpath)[0]
+        pod_is_result = pod.xpath(pod_primary_xpath)
+
+        subpods = pod.xpath(subpods_xpath)
+        if not subpods:
+            continue
+
+        # Appends either a text or an image, depending on which one is more suitable
+        for subpod in subpods:
+            content = subpod.xpath(plaintext_xpath)[0].text
+            image = subpod.xpath(image_xpath)
+
+            if content and pod_id not in image_pods:
+
+                if pod_is_result or not result_content:
+                    if pod_id != "Input":
+                        result_content = "%s: %s" % (pod_title, content)
+
+                # if no input pod was found, title is first plaintext pod
+                if not infobox_title:
+                    infobox_title = content
+
+                content = replace_pua_chars(content)
+                result_chunks.append({'label': pod_title, 'value': content})
+
+            elif image:
+                result_chunks.append({'label': pod_title,
+                                      'image': {'src': image[0].xpath(img_src_xpath)[0],
+                                                'alt': image[0].xpath(img_alt_xpath)[0]}})
+
+    if not result_chunks:
+        return []
+
+    title = "Wolfram|Alpha (%s)" % infobox_title
+
+    # append infobox
+    results.append({'infobox': infobox_title,
+                    'attributes': result_chunks,
+                    'urls': [{'title': 'Wolfram|Alpha', 'url': resp.request.headers['Referer']}]})
+
+    # append link to site
+    results.append({'url': resp.request.headers['Referer'],
+                    'title': title,
+                    'content': result_content})
+
+    return results